Sharp turn steering apparatus for vehicles



March 10, 1953 E. M. MCELHINNEY EI'AL 2,631,045

SHARP TURN STEERING APPARATUS FOR. VEHICLES Filed July 50, 1949 4 Sheets-Sheet 1 JNVENTORS $2122 1 7. inflhznngy March 10, 1953 E. M. MCELHINNEY ET AL 2,631,045

SHARP TURN STEERING APPARATUS FOR VEHICLES Filed July 50, 1949 4 Sheets-Sheet 2 INVENTORS frz'c ihz. 37? 2722121721551 :7. a. wad/79 March 10, 1953 E. M. MCELHINNEY EI'AL 2,631,045

SHARP TURN STEERING APPARATUS FOR VEHICLES Filed July 30. 1949 4 Sheets-Sheet 3 IN V EN TORS March 10, 1953 E. M. M ELHINNEY EI'AL 2,631,045

SHARP TURN STEERING APPARATUS FOR VEHICLES Filed July 30, 1949 4 Sheets-Sheet 4 IN VEN TORS 5-7: 0 1. foahajs fil'onggz;

Patented Mar. 10, 1953 UNITED STATES ATENT OFFICE SHARP TURN STEERING APPARATUS FOR VEHICLES Eric M. McElhinney, Dysart, and Theodore A. Podhajsky, Traer, Iowa 3 Claims.

This invention relates generally to steering mechanisms for transversely spaced vehicle front steering wheels having relatively movable spindles, and in particular to a steering mechanism for a farm wagon having .a front axle provided with spindle mounted wheels.

Many of the farm wagons of four wheel type now in common use are generally incapable of making a sharp turn commensurate with the turning radius of a usual tricycle type tractor. This is due either to the fact that the wagon steering apparatus does not provide for a substantially one-hundred eighty degree turning movement of the front wheels, or to the fact that when such turning movement is provided the wagon tongue, in afull-turned position there for, is in a forwardly inclined position relative to the wagon front axle. As a result the front wheels, during a turning movement, are often times skidded along the ground and the wagon tongue is either bent, when made of metal, or broken when made of wood.

It is an object of this invention, therefore, to provide an improved steering apparatus for a vehicle.

Afurther object of this invention is to provide a steering apparatus for a farm wagon which permits the wagon to easily follow the sharp turning movements of a tricycle or row crop tractor.

Yet another object of this invention is to provide a wagon steering apparatus capable of negotiating a sharp turn with a substantial elimination of any front wheel skidding or bending strain on the wagon tongue.

A still further object of this invention is to provide a wagon steering aparatus of a simple and compact construction, quiet and efficient in operation, and adapted to be assembled on a wagon without interfering in any way with the free movement of the wagon tongue and steering wheels to a sharp-turn position.

Yet another object of this invention is to providea wagon steering apparatus of a construction such that the turning radii of the steering wheels, in a sharp turn, intersect within the transverse dimension or wheel tread of the wagon.

A feature of this invention is found in the provision of a steering apparatus for a vehicle having a front axle with pivoted spindles, and a draft member or tongue pivoted on the axle for horizontal movement, in which each spindle carries a fixed horizontal cam and the draft member a pair of superposed horizontal cams, movable with the draft member, and arranged concentrically 2 relative to the pivot "for the draft member. A single cable is secured under tension about all of the cams, the contours .of which are such that the cable tension is substantially uniform for all moved positions of the draft member and the draft member is maintained in a substantially parallel relation with the wheel leading in the direction of a turn.

Yet another feature :of this invention is found in the provision of a steering apparatus fora vehicle having a front axle with pivoted wheel spindles and a pivoted horizontally movable draft member, in which cooperating horizontal cams on the spindles and draft member are connected through a flexible means and relatively constructed to move the front wheels through .a sharp turning movement of substantially one hundred eighty degrees, with the radii of the wheels in a sharp-turn position intersecting at a point within the longitudinal confines of the front axle.

Further objects, features and advantages of this invention will appear from the following description when taken in connection with the accompanying drawings, in which:

Fig. 1 is a plan view of a farm wagon embodying the steering apparatus of this invention, with the steering apparatus being shown in a straight pull position therefor;

Fig. 2 is an enlarged foresho-rtened sectional view as seen along the line 22 in Fig. 1, with certain parts removed for the purpose of clarity;

Fig. 3 is an enlarged-sectional detail view taken on line 3-3 in Fig. 1;

Fig. 4 is a detail perspective view of a lever member embodied in the steering apparatus of this invention;

Fig. 5 is a detail perspective view of a cam member which forms a part of the steering apparatus of this invention;

Fig. 6 is a sectional view as seen "along the line 6-6 in Fig. 2 with certain parts being broken away to more clearly show the construction of the steering apparatus;

Figs. 7, 8 and '9 are plan views of the front. end of the wagon in Fig. 1, showing the steering apparatus of this invention in changed positions, relative to its illustration in Fig. 1.; i

Fig. 10 is an enlarged sectional detail view taken along the line Ill-Ill inFig. 1,; and

Fig. 11 is a diagrammatic plan view of the wagon in Fig. 1, showing the turning radii of the front wheels for various steering positions therefor.

With reference to the drawings the steering apparatus of this invention is illustrated in Figs;

1 and 2 in assembly relation with a wagon having a front axle |5 equipped at its opposite ends with pivoted spindles It for supporting front steering wheels I1 and H3. The rear axle |9 (Figs. 1 and 10) carries fixed spindles 2| for rear wheels 22 and 23.

Extended rearwardly from the front axle i5 is a tubular reach 24 having front axle braces 25 (Fig. l). The rear end 2'! of the reach 24 is rotatably extended through an opening 28 formed in the rear axle i9 (Figs. 1 and 10). A rear axle brace structure 29, for the reach 24, has its front end 3| rotatably mounted on the reach, and is maintained against movement longitudinally of the reach by an adjustable locking means, indicated generally at 32. The locking means 32 is adjustable longitudinally of the reach 24 to provide a variable wheel base for the wagon. Bolsters 33 and 34 are suitably mounted on the front axle I5 and rear axle |9, respectively.

The steering apparatus of this invention includes a pair of like cam members 36 and 36a (Figs. 1, 2 and 6) which are fixed in a common horizontal plane on the front wheel spindles H5 at positions below the front axle 15. As best appears in Fig. 6, the earns 33 and 35a are of an irregular shape, with each thereof having one side 38 of a semi-circular contour and an opposite side 39 of a substantially flat or linear contour, and are formed in their peripheries with cable-receiving grooves 37.

A second pair of like cams 4| and Ma are assembled as a unit with the rear section 42 of a wagon tongue, indicated generally at 43. The tongue section 42 (Figs. 3 and 4) is of a substantially U-shape with its legs 44 and 44a arranged in a vertically spaced relation. Integrally formed at the front end or base 45 of the tongue section 42 is a transverse bearing sleeve 41. The rear or free ends 48 and 48a of the legs 44 and 44a, are formed with oppositely extended lateral projections 49 and 49a, the rear edge portions of which, as indicated at 5| and 5|a, are of a circular contour.

The cams 4| and Ma are assembled in a superposed relation between the legs 44 and 44a of the tongue section 42 in relatively reversed positions and in a concentric relation with aligned bolt-receiving openings 52 formed in the leg members 44 and 44a.

. With reference to Figs. 5 and 6, it is seen that each cam 4| and Ma constitutes substantially a ninety degree segment of a substantially triangular shape with side portions53 and 54 of reversely curved contours, and a base portion 55 of a convexly curved contour corresponding in size and shape to the contours of the rear edge portions 5| and 5|a of the leg members 44 and 44a, respectively, on the tongue section 42.

In the assembly of the cams 4| and 4m with the tongue section 42, the cam 4| is arranged between the leg members 44 and 44a at a position against the inner side of the leg 44 with its base portion 55 mated or flush with the rear edge portion 5| of the leg member 44. The cam Me is positioned between the leg'members 44 and 44a, and against the inner surface of the leg 44a with its base portion 55 in a mating relation with the rear edge portion 5la of the leg 44a. The cams 4| and Ma are maintained in fixed positions relative to their corresponding legs 44 and 4411 by countersunk screws 51 extended through openings 58 in the legs 44 and 44a for engagement within threaded openings 59 formed in the cams 4| and Ma.

When thus assembled within the tongue sec- .4 tion 42, the cams 4| and 4|a are in a superposed or vertically spaced relation, with the junction of their side portions 53 and 54 overlapping each other. This overlapping of the cams 4| and 4|a takes place between the bolt openings 52 in the tongue section 42 and the overlapped portions of the cams 4| and Ma are formed with bolt openings 5| in coaxial alignment with the bolt openings 52 in the tongue section 42.

The unit assembly of the tongue section 42 and cams 4| and Ma is pivotally supported for movement in a horizontal plane at a position forwardly of the front axle l5 by the provision of means including a U-shape bracket 62 (Figs. 2 and 3), of a substantially U-shape, having its base 53 secured, as by welding, to the front side 64 of the axle |5, and its leg members 66 projected forwardly from the axle l5 in a horizontal vertically spaced relation. The tongue section 42 and bracket 52 are relatively constructed such that the section 42 is receivable within the bracket 52 with the outer surfaces of its legs 44 and 44a. in bearing engagement with the inner surfaces of the bracket legs 65. A pivot bolt 6'! is extended through the bracket legs 66, and the openings 52 and 6| in the tongue section 42 and cams 4| and 4|a, respectively.

The rear end 53 of the front tongue section 69 (Figs. 3 and 6) terminates in a pair of transversely spaced arms adapted to straddle opposite ends of the bearing sleeve 47. A pivot bolt 72, extended through the arms H and the sleeve 41 pivotally supports the front tongue section 59 for up and down movement. It is seen, therefore, that the rear tongue section 42 constitutes a pivoted lever, and the front tongue section 59, an actuating member for pivotally moving the rear tongue section 42 in a horizontal plane. In other words, in instances where the steering apparatus of this invention is applied to a selfpropelled vehicle, a suitable gear or link system operated by a steering wheel and connected with the lever 42 may be substituted for the tongue section or actuating member 69.

In the assembly of the cams 36 and 36a on the wheel spindles I6, the cam sides 38 are positioned outwardly, or adjacent to their corresponding front wheels H and I8 when the tongue 43 is in a straight-pull position, as shown in Figs. 1 and 6. To accomplish a turning movementof the front wheels I! and |8 in response to a pivotal movement of the tongue section or lever 42 there is provided a single flexible member such as a cable 14 having one end 13 adjustably secured at 11 to the front side portion 54 of the cam 4| (Fig. 6). The cable '14, from its secured end 76, is supported within a peripheral groove F8, as shown in Fig. 2, formed in the side portions 53 and 54 of the cam 4|, and is then extended rearwardly for support within the groove 31 in the cam 36, and on leaving the forward end of the cam 36 is extended longitudinally of the axle [5 at a position forwardly thereof to the forward end of cam 33a for reception within the groove 31 formed in the cam 3511. From the rear end of the cam 36a the cable is received within the groove 78 formed in the cam 4|a for the adjustable attachment of its opposite end 19 at 8| to the front or side portion 54 of the cam 4|a. Adjustment of the cable 14 is desired to place the cable under initial tension so as to eliminate any slack therein. Suitable clips or clamps 82 on the earns 35 and 35a hold the cable 14 against any slipping movement relative to such cams.

The contour of the cams 36 and 35a relative to the contour of the cams 4| and Ma is such that at any pivotally moved position of the lever or tongue section '42, tom turn provideior a pivotal movement of the spindles [-6 through the cam 35 and 35a and cable 74, the initial cable tension is uniformly maintained. In other words, the movement of the cable 14 off of one cam and about another cam takes place at a substantially uniform linear rate of movement.

In the operation of the steering apparatus, assume the tongue is to be in its straight pull position illustrated in Figs. 1 andB. In this position the cams 3t and 36a, and ll and 41a, are symmetrically arranged relative to the longitudinal axis of the lever or tongue section 42. On movement of the tongue 43 in a right hand "turn, from its position shown in Figs. -1 and 6 to its position shown in Fig. 7, the cams 36 and 35a are rotated in a-clockwise direction, as viewed'in these figures, but at relative speedsso that the wheel 11., leading in the direction of the turn, is moved at a faster rate than the trailing wheel :18. Stated otherwise, even though the length ofccable l isupported between the cams .36 and 36a moves at the same linear rate of speed over its entire length, the contour of the cams :35 :and 36a relative to their support on the spindles It provides for a slower pivotal movement of the cam 36a relative to the cam 35. In like .manner, the contour of the cams 35 and 36a, relative to the contour and assembly of the-cams M and Ma, maintains .a uniform tension in those parts of the cable supported between corresponding cams36 and 4|, and 36a and Ma. It will be noted further, that during this turning movement the tongue 43, and in turn the tongue section or lever 42, is maintained in a parallel relation with the planeof the leading wheel 17.

On a continued turning movement to the right of the tongue 23 from its position shown in Fig. '7, to its. position shown in Fig. 8 in which the leading wheel I! is in a parallel relation with the axle I5 and located rearwardly of the axle, it will be seen that the parallel relation between the tongue 53 and plane of the leading wheel I! is maintained. For a completed sharp turning movement to the right, as shown in Fig. 9, it is seen that the lead wheel I! has been turned through an angular distance greater than ninety degrees, from its position shown in Fig. 1, while the trailing wheel I8 has been moved through an angular distance of less than ninety degrees rela-- tive to a straight-ahead position therefor, as shown in Fig. 1. At this sharp-turned position, the tongue 43 is inclined rearwardly relative to the front axle l5 and is in a parallel relation with the lead wheel H.

For a sharp turning movement toward the left, the wheel I8 is turned at a faster rate than the wheel ll, with the tongue 33 being maintained in a parallel relation with the plane of the lead wheel It.

With reference to Fig. 11, the tongue 43 is shown in full lines at a position corresponding to its right-turned position in Fig. '7. At this position the radii l'ia and I80. for the wheels I1 and i8, respectively, intersect at a point located outside of the transverse dimensions or wheel tread of the wagon. On movement of the tongue 43 to its dotted-line position, indicated at A in Fig. 11, and corresponding to the turned position of the tongue 43 in Fig. 8, the radii Ill) and it!) for the front wheels I? and H3, respectively, intersect at a point 15a which is in a line 80 parallel with the front axle l5 and common to the point 6 is within the transverse confines bf the wagon and in a plane extended longitudinally of the wagon common to the spindle 1'6 .for :the lead wheel I 7.

With the tongue 43 moved to its full-turned position indicated at B in dotted lines inFig. 511, and corresponding to its positionshowniin Fig. .9, the radii I10 and I380 for the wheels J1 and 1'8, respectively, intersect at :a point 351) on the All] at a position approaching :a mid-point :of the wagon wheel tread. For 'a given Wheel base :and tread of a. wagon, and as illustrated in Fig. 1-1,, the line .80 may be coincident with the axis .of the rear axle 1 9.. However, :even though variations as to wheelbase and wheel .tread should result in wagons of different types, any skidding 'of the front wheels .11 and 18 :or bending of the tongue 43, :during "a turning action, substantially reduced byvirtue of the fact that the tongue 43 is always maintained in a parallel relation with the plane of the front wheel leading in the direction of the turn.

From a consideration of the above description, it is seen that the invention provides a steering .ap- .paratus for a wagon which is :of a simple and compact construction andoperable to accomplish a sharp turn of the wagon with .a substantial elimination of any skidding .of the front wheels, or bending strain on the tongue 43. Further, by virtue of the cam .and cable arrangement, :the steering apparatus is both positive and substantially noiseless in operation, with .the cams :being assembled relative to .the wagon so as to permit .a free turning movement without interference with the wagon or the wheels. As best appears 'inFigs. 2 and 3, it isseen that the cam-.5138 and 36d are arranged in a common horizontal plane which is located intermediate the plane of the cams 4| and 41a so as to eliminate any wearing of the cable over those crossed portions thereof extended between the cams 3'8 and 36a, and the cams 36 and ll and 36a and lla.

Although the invention has been described with respect to a preferred embodiment thereof, it is to be understood that it is not to be so limited since changes and modifications can be made therein which are within the full-intended scope of this invention, as defined by the appended claims.

We claim:

1. A steering apparatus for a vehicle having a front axle provided with a pair of pivoted front- Wheel spindles comprising, horizontally disposed cam members mounted on said spindles for pivotal movement therewith, a pivoted lever member, means supporting said lever member on said axle for pivotal movement in a horizontal plane, a pair of vertically spaced cam members, corresponding to the cam members on said spindles, and mounted on said lever member for concurrent pivotal movement therewith ?about a common axis, with the cam members on said spindles being arranged in a common plane disposed between the planes of said vertically spaced cam members, a flexible member trained about said cam members having the opposite ends thereof secured to said vertically spaced cam members, with the cam members on said spindles being eccentrically mounted on said spindles so that the peripheral increments of the effective working surfaces thereof are located unequal distances from the axes of said spindles, and said vertically disposed cam members having effective working surfaces formed and ar- 15. It will be noted further, that the point 15a ranged relative to the effective cam surfaces on said spindle cam members whereby said'fiexible member is maintained under constant tension for all moved positions of said lever member, and an actuating member for pivotally moving said lever member 2. A steering apparatus for a vehicle having a front axle provided with a pair of pivoted frontwheel spindles comprising, a pair of oppositely arranged horizontal cam members mounted on said spindles for pivotal movement therewith, a pivoted lever, means pivotally supporting said lever member on said axle for horizontal movement, a pair of vertically spacedoppositely arranged cam members mounted on said lever member for concurrent pivotal movement therewith, with the adjacent sides of the cam members on said lever constituting the effective working portions thereof, a flexible member having one end portion secured about one of the cam members on said lever and extended therefrom about one of said spindle cam members, then longitudinally of said axle about the second one of said spindle cam members, and having its pposite end portion secured to the second cam member on said lever, with said spindle cams having curved eifective working surfaces forming segments of circles the centers of which are olfset relative to the axes of said spindles so that the peripheral increments of said segments are located unequal distances from the spindle axes,

and said cam members on said lever having a contour relative to the contour of said spindle cam members such that the tension in said flexible member is substantially constant for all moved positions of said lever member, and an actuating member for pivotally moving said lever.

3. A steering apparatus for a vehicle having a front axle provided with a pair of pivoted frontwheel spindles comprising, a draft member,

means pivotally supporting said draft member on said front axle for pivotal movement about a vertical axis, a pair of vertically spaced horizontal cam members mounted on said draft memher for pivotal movement therewith, said cams being arranged in an overlapping relation concentric With said vertical axis, a pair of horizontal cam members corresponding to and fixed on said wheel spindles, with each of said spindle cam members having one side of a semi-circular contour, located adjacent to a corresponding front wheel and with a spindle cam member being mounted on a wheel spindle such that said one side is non-symmetrical relative to the axis of a wheel spindle, and a flexible member extended under tension about all of said cam members having opposite end portions thereof secured to said vertically spaced cam members, said vertically spaced cam members having a contour relative to the cam members on said wheel spindles over those portions thereof contacted by said flexible member, such that the draft member in a steering operation is maintained in a parallel relation with the front wheel leading in the direction of a turn.

ERIC M. MCELHINNEY. THEODORE A. PODHAJSKY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 935,610 Mauksch Sept. 28, 1909 949,202 Shedenhelm Feb. 15, 1910 1,069,810 Riemer Aug. 12, 1913 1,133,875 Monroe Mar. 30, 1915 

